27 research outputs found
Pure psychiatric presentation of the Lewy body disease is depression: An analysis of 60 cases verified with myocardial meta-iodobenzylguanidine study
Objective Parkinson\u27s disease (PD), Parkinson\u27s disease with dementia (PDD) and dementia with Lewy bodies (DLB) were collectively termed Lewy body disease (LBD). Pure psychiatric presentation (PPP) of the LBD may be the fourth subtype in which psychiatric symptoms without definite parkinsonism and cognitive disturbance lasted for many years. The aim of this study is to localize the presence of the PPP in subjects with low uptake of myocardial meta-iodobenzylguanidine (MIBG). Methods Sixty MIBG-verified patients (28 women and 32 men) were classified into three psychiatric pictures; depression (Group D: 27 patients), isolated visual hallucinations (Group V: 16 patients) and psychosis (Group P: 17 patients). Fifty six cases were examined with single photon emission tomography (SPECT) study of the brains in which hypoperfusion lobes were identified in 37 cases and 19 cases showed no abnormality. After that, we determined final diagnoses; PD, PDD, DLB and PPP with an aid of the DSM-IV, the unified Parkinson\u27s disease rating scale (UPDRS) and Mini-mental state examination (MMSE). Results Of Group D patients 40% remained depressive without parkinsonism and about 50% had or developed typical parkinsonism. Most Group P patients developed clinical pictures of PDD or DLB. Statistics provided four combinations: Group V-DLB-occipital lobe hypoperfusion, Group D-PD without SPECT abnormality, Group P-PDD with temporal lobe hypoperfusion and Group D-PPP without SPECT abnormality. Conclusions PPP featured major depressive disorder and can be preparative of incidental LBD and prodromal depression of PD. Psychosis and dementia were of the same quality that characterizes the PDD. Copyright © 2014 John Wiley & Sons, Ltd
Optical Counterparts of X-Ray Point Sources Observed by CHANDRA in NGC5128: 20 New Globular Cluster X-Ray Sources
VLT images in are used to identify the optical counterparts to bright
CHANDRA X-ray points sources discovered by Kraft et al. (2001, ApJ, 560, 675)
in NGC5128. Of a total of 111 X-ray point sources with L_X>2*10^{36} ergs/s
present in a 56 arcmin^2 field centered on this galaxy, 58 have optical
counterparts. Based on the sizes, optical magnitudes and colors, 20 new
globular cluster counterparts of X-ray sources are identified, plus 3
identified based on their sizes. This brings the total number of globular
cluster X-ray sources in this galaxy to 33, and establishes that 30% of the
X-ray point sources in NGC5128 are associated with globular clusters. These
X-ray globular clusters occupy the brightest end of the globular cluster
luminosity function, indicating that bright low-mass X-ray binaries are
preferentially found in massive clusters. Most of the globular clusters with
X-ray sources have red colors, with 1.0<V-I<1.5, indicating that low-mass X-ray
binaries are preferentially formed in metal-rich clusters. The NGC5128 X-ray
globular cluster sources are brighter in comparison with the Milky Way sources:
there are 24 globular clusters with X-ray sources of L_x>10^{37} erg/sec. There
is, however, no globular cluster X-ray source in NGC5128 as bright as expected
for an accreting black hole. In addition, 31 optical counterparts of X-ray
point sources that are not associated with globular clusters are identified.
Finally, 53 X-ray point sources (48% of the population), do not have any
optical counterparts down to the faintest magnitude limits (B=25).Comment: 32 pages, 8 figures; replaced with the accepted version; to appear in
ApJ, January 200
The Star Formation Demographics of Galaxies in the Local Volume
We examine the connections between the current global star formation
activity, luminosity, dynamical mass and morphology of galaxies in the Local
Volume, using H-alpha data from the 11 Mpc H-alpha and Ultraviolet Galaxy
Survey (11HUGS). Taking the equivalent width (EW) of the H-alpha emission line
as a tracer of the specific star formation rate, we analyze the distribution of
galaxies in the M_B-EW and rotational velocity (V_{max})-EW planes.
Star-forming galaxies show two characteristic transitions in these planes. A
narrowing of the galaxy locus occurs at M_B~-15 and V_{max}~50 km/s, where the
scatter in the logarithmic EWs drops by a factor of two as the
luminosities/masses increase, and galaxy morphologies shift from predominately
irregular to late-type spiral. Another transition occurs at M_B~-19 and
V_{max}~120 km/s, above which the sequence turns off toward lower EWs and
becomes mostly populated by intermediate and early-type bulge-prominent
spirals. Between these two transitions, the mean logarithmic EW appears to
remain constant at 30 A. We comment on how these features reflect established
empirical relationships, and provide clues for identifying the large-scale
physical processes that both drive and regulate star formation, with emphasis
on the low-mass galaxies that dominate our approximately volume-limited sample.Comment: 5 pages, accepted for publication in ApJL pending editing for lengt
The Incidence of Highly-Obscured Star-Forming Regions in SINGS Galaxies
Using the new capabilities of the Spitzer Space Telescope and extensive
multiwavelength data from the Spitzer Infrared Nearby Galaxies Survey (SINGS),
it is now possible to study the infrared properties of star formation in nearby
galaxies down to scales equivalent to large HII regions. We are therefore able
to determine what fraction of large, infrared-selected star-forming regions in
normal galaxies are highly obscured and address how much of the star formation
we miss by relying solely on the optical portion of the spectrum. Employing a
new empirical method for deriving attenuations of infrared-selected
star-forming regions we investigate the statistics of obscured star formation
on 500pc scales in a sample of 38 nearby galaxies. We find that the median
attenuation is 1.4 magnitudes in H-alpha and that there is no evidence for a
substantial sub-population of uniformly highly-obscured star-forming regions.
The regions in the highly-obscured tail of the attenuation distribution
(A_H-alpha > 3) make up only ~4% of the sample of nearly 1800 regions, though
very embedded infrared sources on the much smaller scales and lower
luminosities of compact and ultracompact HII regions are almost certainly
present in greater numbers. The highly-obscured cases in our sample are
generally the bright, central regions of galaxies with high overall attenuation
but are not otherwise remarkable. We also find that a majority of the galaxies
show decreasing radial trends in H-alpha attenuation. The small fraction of
highly-obscured regions seen in this sample of normal, star-forming galaxies
suggests that on 500pc scales the timescale for significant dispersal or break
up of nearby, optically-thick dust clouds is short relative to the lifetime of
a typical star-forming region.Comment: Accepted for publication in ApJ; emulateapj style, 30 pages, 18
figures (compressed versions), 3 table